A liquid crystal panel used for a liquid crystal display device such as a liquid crystal television does not emit light itself. Therefore, it requires a backlight device as an external lamp. The backlight device is usually disposed behind the liquid crystal panel (i.e., on an opposite side from a display surface). The backlight device includes a metal or resin chassis, which is a housing, having an opening on a liquid crystal panel side. It also includes many fluorescent tubes (e.g., cold cathode tubes) housed in the chassis as lamps and many pieces of optical members (diffusing sheet and the like) disposed around the opening of the chassis for effectively transmitting light emitted from the lamps toward the liquid crystal panel side. Moreover, connectors may be provided in such a backlight device for connecting the lamps to an inverter. An example of a backlight device including such connectors is disclosed in Patent Document 1.    Patent Document 1: JP-A-2006-344602